Practice question · Multiple choice
Why does a gas expanding freely into an evacuated chamber do no work at all?
Hints
- Work requires an opposing external pressure.
- Expanding into a vacuum means the external pressure is exactly zero.
Show the answer
D. None, because there is nothing to push against
Why
Work is , and throughout a free expansion, so exactly. The gas expands and does nothing, and for an ideal gas it does not cool either, since depends on temperature alone.
Practise Work and the Joule Experiment
The app has 5 more questions on this lesson, and keeps your place in the course. Physics II is free to start.
More questions on Work and the Joule Experiment
- Arrange the steps of Joule’s reasoning in the order they establish internal energy.
- A gas is compressed at a constant external pressure of 200 kPa from 0.050 m³ to 0.020 m³. Compute the work…
- Sort each expression by the kind of system whose work it describes.
- Which processes do zero work on or by a gas?
- Work is path-dependent, yet Joule used mechanical work to establish a unique internal energy function. How…